Case ReportsAngiomyxofibromatous Tumor of the Falx CerebriMedeiros, Fabiola MD*; Scheithauer, Bernd W. MD*; Oliveira, Andre M. MD*; Gregory, Richard S. MD†Author Information *Division of Anatomic Pathology, Mayo Clinic, Rochester, MN †Department of Neurosurgery, Regions Hospital, St Paul, MN Correspondence: Bernd W. Scheithauer, MD, Division of Anatomic Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 Abbreviations: EMA, epithelial membrane antigen, SFT, solitary fibrous tumor. The American Journal of Surgical Pathology: April 2006 - Volume 30 - Issue 4 - p 545-547 Buy Abstract We report a distinctive angiomyxofibromatous lesion arising from the falx cerebri of a 48-year-old woman. The tumor was composed of bland-appearing, spindle, and stellate cells in a myxoid matrix with prominent vascularity. The tumor cells were immunopositive diffusely for vimentin and focally for S-100 protein, but were immunonegative for epithelial membrane antigen, CD34, MIC2, Bcl-2, glial fibrillary acidic protein, cytokeratin CAM 5.2, desmin, and smooth muscle actin. This lesion could not be categorized according to the current World Health Organization classification of tumors of the nervous system, thus underscoring a need to enhance our understanding of myxoid mesenchymal neoplasms and reassess their nosology. © 2006 Lippincott Williams & Wilkins, Inc.